Means for inductively heating flanged articles



July 26, 1949. A. o. WOOD MEANS FOR INDUCTIVELY HEATING FLANGED ARTICLES Filed Aug. 26, 1945 2 Sheets-Sheet l INVENTOR 5124M 0- WA Filed Aug. 26, 1943 y 1949- A. o. WOOD 2,477,029

MEANS FOR INDUCTIVELY HEATING FLANGED ARTICLES 2 Sheets-Sheet 2 'INVENT OR Wa i/n4 Patented July 26, 1949 MEANS FOR INDUCTIVELY HEATING FLAN GED ARTICLES Alden 0. Wood, Parma, Ohio, assignor to The Ohio Crankshaft Company, Cleveland, Ohio, a

corporation of Ohio Application August 26, 1943, Serial No. 500,143

6 Claims.

The present invention 'is an improvement on the methods and apparatus shown and described in my copending applications Serial Nos. 475,833 now Patent No. 2,419,619 issued April 29, 1947 and 476,989 now Patent No. 2,428,303 issued September 30, 1947, filed February 13, 1943 and February 24, 1943 respectively, relates to dual inductive heat treating and is directed chiefly to the hardening of the rim portions of double flanged wheels and similar articles. Heretofore in the manufacture of wheels of this type it has been customary to make the wheels in the form of ferrous castings or rolled forgings. Since these wheels usually run on hard steel rails and carry heavy loads, it is necessary that the treads possess a high degree of strength and be resistant to the kneading action imposed on the treads and which, when the rim is not made of the correct material properly treated, results in the socalled shelling off of surface portions of the tread. Further, one or both flanges of the wheel which serve as means for guiding the wheel along the rail are subject to severe frictional wear and therefore must be hard and possess correct metallurgical structure.

Accordingly, it has been an object of this invention to provide apparatus adapted to harden all wearing surfaces at the rim of such double flanged wheel or similar article. Another object has been to provide means for accomplishing such hardening uniformly. A further object has been to provide apparatus adapted to heat various parts of the rim portion to selected depths to attain correct depths of hardness. An additional object has been to provide means for quenching at the correct rate to attain the desired hardness. Another object has been to provide a method generally applicable to the hardening of such wheels or similar parts. The chief object, however, has been to provide the hereinafter described wheel having tread'and flange portions of desired form and hardness.

With the above and other objects in view which will become apparent from the following description and annexed drawings, the said invention then consists of the hereinafter described and illustrated product together with the method of producing it and the apparatus required for the practice of this method. I

In said annexed drawings:

Fig. 1 illustrates a typical wheelpartly in section, the section showing the general distribution of hardened and otherwise improved metal.

Fig. 2 is a plan view of the heating inductor showing a fragmentary part of the wheel in heating position therein.

Fig. 3 is a side elevation partly in section of the inductor taken in the direction indicated at 3-3 of Fig. 2 and showing a fragment of the wheel inserted therein.

Fig. 4 is a section on an enlarged scale substantially as indicated at 44 of Fig. 3.

Fig. 5 is a fragmentary vertical section showing the quenching member in place relative to the wheel rim.

Referring now to the drawings, particularly Fig. l, the wheel to be heat treated comprises the hub portion I0 and the rim portion indicated generally at H together with the web or plate portion l2. The rim portion comprises the cylindrical tread area I3, inner flange I4 and outer flange IS, the tread and flanges being supported by section l6 lying intermediately between the flanges and the plate. The different cross hatchings indicate three different sections of metal. The metal in all of the three sections is substantially the same chemically, but is different metallurgically, each of the three sections being such as to provide the characteristics desired in that section.

In my improved process the tread and flanges are heated to critical temperature and quenched to provide a hard tread area at [3 resistant to shelling which area extends out into and around the flanges l4 and I5 to provide hard zones along inner lateral flange surfaces at l8 and I9 resistant to frictional wear. The outer lateral surface zones of the flanges, as at 20 and 2|, are provided with hardness substantially equal to that of the tread and inner flange surfaces to add strength and rigidity to the flanges. While the outer areas are being heated to critical temperature to be quenched for hardness, the intermediate section IG is heated to a lesser degree, but sufliciently to add to its physical properties, this section being less hard than the tread and flanges but tougher and more resistant to shock than the hub at II]. All numerals applied to Fig. 1 other than numerals 10 to 20 inclusive as above designated, show the hardness of the metal on the Rockwell C scale at the various points indicated by dots or periods to which these numerals are directed and collectively show the variations in this hardness.

To provide this wheel the apparatus hereinafter described or its equivalent is required. This apparatus comprises the inductor shown in Figs. 24 and the quenching apparatus of Fig. 5. The inductor as illustrated comprises the member 25 connected at 26 to one terminal of the source 21 of high irequency current and members 28 and 29 comprising parallel branches of the return circuit, these branches being joined to form one conductor 30 which in turn is connected :to the other terminal of the high ,irequency source. Conductor 25 is curved to lie generally parallel to and in closely spaced relation with the cylindrical tread portion l3 of the wheel. -:Side con.- ductors 28 and 29 may assume avariety-of iorms, either straight as shown or curved, to control the depth of the hardened gqnes particularly in the flanges as measured radially of the wheel.

While Fig. 4 shows all of the three conductors comprising the inductor as being of the same general size iand form, these conductors are fre- .ouently different .to provide correct-distribution of heating current in tread and flanges. For

' instance,etheconductor 25 lying along the tread plication .of inducing current to the inductor.

This -is accomplished .by supporting the wheel on-the support 35 which is rotated by any convenient means during the heat treating cycle. Usually it is desirable to rotate the wheel at the maximum rate consistent with the size and weight of the wheel to'reduce to a minimum the interval during any element of the rim is outside the heating field. Further, it is usually desirable to extend the inductor as far as :con-

venient peripherally along the rim to prolong as 'much as possible the are through which heating occurs.

To that end the central conductor 25 is often extended through an arc of nearly 180 and side conductors 28 and 29 are curved to extend in a direction generally parallel with this central conductor to not only avoid interfering with the hub of the wheel but to more effectively concentrate heating flux in the rim portion.

4 dicated by the coarse cross hatching are accomplished by selecting current of the correct frequency and then regulating the power input and time intervals during which power is applied at the different rates. In some cases it is desirable to change the frequency, finishing the heating with current of a higher frequency than that used in the earlier stages of the heating.

Numerous modifications in the general arrangement of the apparatus will become apparent -;to those skilled in the art. "For example, the

lateral conductors in many cases are -curved to large .orwhen the flange is a straight or curved projection on a fixed member other than a Wheel, the conductors are both made to extend along the entire length of the flange, as for instance Aiter heating has been completed quenching is accomplished by moving the inductor away from the wheel, usually by rotating the transformer to which the terminals of the inductor are attached, the transformer being supported to turn on a verticalaxis, and then lowering the cylindrical quenching shell 36 over the wheel. Quenching fluid is supplied at suitable pressure from supply valve 31 and is projected through a large number of orifices such as 38 onto the indic ted t e medium paced cross ha ching w hout disturb n the o gin l heat treatmen b of the hub and inner portions of the plate into extend around substantially the entire periphery of the wheel when the flange is a part of a wheel as illustrated. In such installations [t e two conductors are not ;permanently.gioined as illustrated-in the. present figures, but are .ioi i fid to ether when put in :place on the wheel to complete the series circuit through them.

QHd naI l-y the .ccmductors fare of tubular .construction to provide means tor the circulation of de line fluid and to more economically carry hi h f ecucncy current.

Qth r mcdes ,of applying the .prinoiplenf my inven ion may be employed-instead .of the .one

explained, modifications being made in details of the product described as well as in the method of producin it and in the form of apparatus recuired for accomplishing the method explained, provided those modifications .or their equivalents aredefined by the following claims.

I, therefore, particularly point out and dist n tly la m as m inven ion:

1. Aninductor gfior heating tread and flange parts of a rim portion ,of .a wheel comprising an inner conductor member having a curved suriace disposed to lie in parallel closely spaced relation with a generally cylindrical surface of the tread part, said conductor member having a lateral surface disposed to lie in closely spaced relation with an inner tread adjacent face of the flange, an outer conductor member disposed to lie generally parallel with an outer circular face of the wheel and to extend as a chord acrossthe circular face, the circular face having a circumference defined .by an outer periphery of the flange, a part of the chordal conductor member being disposed to pass close to a side of the flange andhaving an end adapted to extend beyond the outer periphery of the flange, a center part of the chordal conductor member being disposed to lie generally radially inward from the flange and having end adjacent parts disposed to lie opposite to parts .of the'fiange and with intermediate parts Varying generally in distance from the flange, the distance being a minimum substantially adjacent to an outer periphery of the wheel and a maximum at a center part of the chordal conductor membe to vary heating proximityof the flange with thechordal conductor member from'a maxiadiacent to its end to a minimum at its c nter, c nductin means adapted to extend a o s a pe ipheral part f the flange to connect the end of the chordal conductor member extending beyond the flange to an end of the curved conductor member, and means for supplying inducing current to flow in series through the curved conductor member and chordal conductor member to heat simultaneously the cylindrical surface of the tread and inner and outer surface zones of the flange.

2. In apparatus for heating tread and flange parts of a rim portion of a wheel, the wheel having a rim supporting plate, an inductor comprising an inner conductor member having a curved surface disposed to lie in parallel closely spaced relation with a generally cylindrical surface of the tread part of the wheel, said conductor member having a lateral surface disposed to lie in closely spaced relation with an inner tread adjacent face of the flange part, an outer conductor member disposed to lie generally parallel with an outer circular face of the wheel and to extend as a chord across the circular face, the circular face having a circumference defined by an outer pe riphery of the flange, the chordal conductor member having a substantially flat side disposed to present a relatively flat surface to lie adjacent to the wheel, the flat side having an outer edge which at its center is disposed to lie in current inducing proximity with an inner peripheral part of the flange, an inner edge of the flat side of the chordal conductor member being disposed to bridge a space adjacent to the flange and to lie relatively remote from the flange and from a plate part of the wheel, an end of the chordal conductor member being adapted to extend beyond outer peripheral parts of the flange, a conductor connecting the end of the chordal conductor member to an end of the curved conductor member, and means for supplying inducing current to flow in series through the curved conductor member and chordal conductor member to simultaneously heat the flange and the cylindrical surface of the tread.

3. In apparatus for heating tread and flanges 40 of a double flange wheel, an inductor comprising a generally hollow central conductor adapted to li between the flanges and two outer conductors adapted to lie along opposite circular faces of the wheel and outside of the flanges, the central con- 45 radially beyond outer peripheries of the flanges 55 and serving as means for joining the outer conductors to the center conductor, and means for supplying inducing current to flow in series through the center conductor and outer conductors, the outer conductors being electrically in 0 parallel.

4. An inductor for heating tread and flange parts of a rim portion of a metallic wheel comprising an inner conductor having a curved surface disposed to lie in parallel closely spaced 65 relation with a generally cylindrical surface of the tread part, said inner conductor having a lateral surface disposed to lie in closely spaced relation with an inner tread-adjacent face of the flange,

an outer conductor disposed to lie generally 70 parallel with an outer circular face of the wheel and to extend across the circular face, the circular face having a circumference defined by an outer periphery of the flange, a part of the outer conductor being disposed to pass close to a side of 75 generally the flange and having an end adapted to extend beyond the outer periphery of the flange, a central part of the outer conductor being disposed to lie generally radially inward from the flange and having end parts disposed to lie opposite parts of the flange and with intermediate parts varying generally in distance from the flange, the distance being a minimum substantially adjacent to an outer periphery of the wheel and a maximum at a central part of the outer conductor to vary heating proximity of the flange with the outer conductor from a, maximum adjacent to its ends to a minimum at its center, conducting means adapted to extend across a peripheral part of the flange to connect the end of the outer conductor extending beyond the flange to an end of the inner conductor, and means for supplying inducing current to flow in series through the inner and the outer conductors to heat simultaneously the cylindrical surface of the tread and inner and outer surface zones of the flange.

5. An inductor for heating tread and flange parts of a rim portion of a metallic wheel comprising an inner generally curved conductor having an curved surface disposed to lie in parallel closely spaced relation with a generally cylindrical surface of the tread part, said inner conductor having a lateral surface disposed to lie in closely spaced relation with an inner tread-adjacent face of the flange, an outer conductor disposed to lie generally parallel with an outer circular face of the wheel and to extend across the circular face, the circular face having a circumference defined by an outer periphery of the flange, a part of the outer conductor being disposed to pass close to a ide of the flange and having an end adapted to extend beyond the outer periphery of the flange, the outer conductor lying generally along a chord subtending an arc of the inner conductor, a conductor joining the extend-ing end of the outer conductor to an end of the inner conductor to connect said conductors in series, and means for supplying inducing current to flow in series through said conductors to heat simultaneously a surface zone of the tread and inner and outer surface zones of the flange.

6. Apparatus for induction heating of the rim and flange of a flanged type roller or the like which comprises a curved induction element arranged for disposal adjacent the rim and at one side of the flange during rotation of the roller, and another induction element cooperating with the first element to produce a heat inducing field and disposed at the opposite side of the flange on a line intersecting the arc of the first element.

ALDEN 0. WOOD.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 1,983,177 Lee Dec. 4, 1934 2,103,834 Tyson Dec. 28, 1937 2,144,378 Kennedy Jan. 17, 1939 2,164,310 Denneen et a1. July 4, 1939 2,282,322 Denneen et a1 May 12, 1942 2,338,496 Denneen et a1 Jan. 4, 1944 2,356,150 Denneen et a1 Aug. 22, 1944 OTHER REFERENCES A. P. 0. Application of Gumprecht, Serial No. 387,342, published June 1, 1943. 

